rule win_starcruft_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        version = "1"
        description = "Detects win.starcruft."
        info = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.6.0"
        signator_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.starcruft"
        malpedia_rule_date = "20221118"
        malpedia_hash = "e0702e2e6d1d00da65c8a29a4ebacd0a4c59e1af"
        malpedia_version = "20221125"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    /* DISCLAIMER
     * The strings used in this rule have been automatically selected from the
     * disassembly of memory dumps and unpacked files, using YARA-Signator.
     * The code and documentation is published here:
     * https://github.com/fxb-cocacoding/yara-signator
     * As Malpedia is used as data source, please note that for a given
     * number of families, only single samples are documented.
     * This likely impacts the degree of generalization these rules will offer.
     * Take the described generation method also into consideration when you
     * apply the rules in your use cases and assign them confidence levels.
     */


    strings:
        $sequence_0 = { 0355b4 8b45f0 8d8c1056b7c7e8 894df0 8b55f0 }
            // n = 5, score = 100
            //   0355b4               | add                 edx, dword ptr [ebp - 0x4c]
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]
            //   8d8c1056b7c7e8       | lea                 ecx, [eax + edx - 0x173848aa]
            //   894df0               | mov                 dword ptr [ebp - 0x10], ecx
            //   8b55f0               | mov                 edx, dword ptr [ebp - 0x10]

        $sequence_1 = { 8b55f8 c7420400000000 8b4508 8945f4 8b4df4 0fb711 83fa3c }
            // n = 7, score = 100
            //   8b55f8               | mov                 edx, dword ptr [ebp - 8]
            //   c7420400000000       | mov                 dword ptr [edx + 4], 0
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   8945f4               | mov                 dword ptr [ebp - 0xc], eax
            //   8b4df4               | mov                 ecx, dword ptr [ebp - 0xc]
            //   0fb711               | movzx               edx, word ptr [ecx]
            //   83fa3c               | cmp                 edx, 0x3c

        $sequence_2 = { c78528feffff00000000 eb0f 8b8528feffff 83c001 898528feffff 83bd28feffff04 7d2b }
            // n = 7, score = 100
            //   c78528feffff00000000     | mov    dword ptr [ebp - 0x1d8], 0
            //   eb0f                 | jmp                 0x11
            //   8b8528feffff         | mov                 eax, dword ptr [ebp - 0x1d8]
            //   83c001               | add                 eax, 1
            //   898528feffff         | mov                 dword ptr [ebp - 0x1d8], eax
            //   83bd28feffff04       | cmp                 dword ptr [ebp - 0x1d8], 4
            //   7d2b                 | jge                 0x2d

        $sequence_3 = { 88500f 8b4ddc c1e904 81e1ff000000 8b5508 884a0e c745fc00000000 }
            // n = 7, score = 100
            //   88500f               | mov                 byte ptr [eax + 0xf], dl
            //   8b4ddc               | mov                 ecx, dword ptr [ebp - 0x24]
            //   c1e904               | shr                 ecx, 4
            //   81e1ff000000         | and                 ecx, 0xff
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]
            //   884a0e               | mov                 byte ptr [edx + 0xe], cl
            //   c745fc00000000       | mov                 dword ptr [ebp - 4], 0

        $sequence_4 = { 51 e8???????? 85c0 750c 8b55fc 52 ff15???????? }
            // n = 7, score = 100
            //   51                   | push                ecx
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   750c                 | jne                 0xe
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   52                   | push                edx
            //   ff15????????         |                     

        $sequence_5 = { c645f301 ebd0 eb04 c645f300 eb04 c645f300 8b4df4 }
            // n = 7, score = 100
            //   c645f301             | mov                 byte ptr [ebp - 0xd], 1
            //   ebd0                 | jmp                 0xffffffd2
            //   eb04                 | jmp                 6
            //   c645f300             | mov                 byte ptr [ebp - 0xd], 0
            //   eb04                 | jmp                 6
            //   c645f300             | mov                 byte ptr [ebp - 0xd], 0
            //   8b4df4               | mov                 ecx, dword ptr [ebp - 0xc]

        $sequence_6 = { 32c0 e9???????? 8d9524fdffff 52 ff15???????? 83c001 }
            // n = 6, score = 100
            //   32c0                 | xor                 al, al
            //   e9????????           |                     
            //   8d9524fdffff         | lea                 edx, [ebp - 0x2dc]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   83c001               | add                 eax, 1

        $sequence_7 = { 8bec 81ec50020000 a1???????? 33c5 8945f8 68???????? }
            // n = 6, score = 100
            //   8bec                 | mov                 ebp, esp
            //   81ec50020000         | sub                 esp, 0x250
            //   a1????????           |                     
            //   33c5                 | xor                 eax, ebp
            //   8945f8               | mov                 dword ptr [ebp - 8], eax
            //   68????????           |                     

        $sequence_8 = { ff15???????? 8b4d08 51 ff15???????? 8b55fc 8b0a 33d2 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   51                   | push                ecx
            //   ff15????????         |                     
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   8b0a                 | mov                 ecx, dword ptr [edx]
            //   33d2                 | xor                 edx, edx

        $sequence_9 = { 8d95d8fdffff 52 ff15???????? e8???????? }
            // n = 4, score = 100
            //   8d95d8fdffff         | lea                 edx, [ebp - 0x228]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   e8????????           |                     

    condition:
        7 of them and filesize < 294912
}